I've got 2x1TB WD My Passport USB drives - one is my TimeMachine, always connected, the other is for a weekly Carbon Copy Clone. I also have three 128GB SanDisk USB sticks which I use with CCC. One for Music, one for Pictures/Photos and one for my 'Stuff" (eg documents and files) which backup when connected. I've a USB dock stuck on my desktop with a little bit of blutack for easy connection. Some stuff, but not much, is on iCloud for if I need access through my pad/phone.